• Fisheries and Aquatic Sciences
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• v.13 no.2
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• pp.127-132
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• 2010

A study was conducted to investigate the effects of dietary lipid sources on the growth and fatty acid composition of juvenile sea cucumber. For 12 weeks, three replicate groups of sea cucumber (average weight 1.4 g) were fed one of three diets, containing squid liver oil (SLO), soybean oil (SO), or linseed oil (LO) as a dietary lipid source, or a control diet (CON) without added lipids. Sea cucumber survival was not significantly different among dietary treatments (P>0.05). The highest weight gain was observed in sea cucumber fed the SLO diet, whereas the weight gain of sea cucumber fed the SO diet was the lowest among dietary treatments (P<0.05). No significant differences were found in the moisture, crude protein, crude lipid, and ash contents of whole sea cucumber body among dietary treatments (P>0.05). Concentrations of 20:5n-3 and 22:6n-3 were significantly higher in sea cucumber fed the SLO diet than in those fed on the other diets. The highest 18:2n-6 and 18:3n-3 contents were observed in sea cucumber fed the SO and LO diets, respectively. The results of this study suggest that squid liver oil could be used as a good lipid source in formulated diets for juvenile sea cucumber.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.51 no.2
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• pp.187-198
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• 2018

The monthly salinity maps from Aquarius satellite covering the entire East Sea were produced to analyze the low-salinity water appearing in fall every year. The low-salinity water in the northern East Sea began to appear in May-June, spreading southward along the coast and eastward north of the subpolar front. Low-salinity water from the East China Sea entered the East Sea through the Korea Strait from July to September and was mixed with low-salinity water from the northern East Sea in the Ulleung Basin. The strength of the low-salinity water from the East China Sea was dependent on the strength of the southerly wind of the East China Sea in July-August. The salinity reaches a minimum in September with a distribution parallel to the latitude of $37.5^{\circ}N$. In October, low salinity water is distributed along the mean current path and subpolar front and the entire East Sea is covered with the low salinity water in November. Water with salinity larger than 34 psu starts to flow into the East Sea through the Korea Strait in December and it expands gradually northward up to the subpolar front in January- February.

• Journal of the Society of Naval Architects of Korea
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• v.48 no.3
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• pp.254-259
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• 2011

The first Korean-made icebreaking research vessel "ARAON" had her second sea ice trial in the Arctic Ocean in Aug. 2010 after her first voyage to Antarctic Ocean in Jan. 2010 to gather various material and strength characteristics of sea ice. This is a detail report of ARAON 2010 summer Arctic voyage and this paper describes a standard test procedure to obtain proper sea ice data which provide basic information to estimate ice loads and icebreaking performance of the ship. The data gathered from sea ice in the Chukchi Sea and Beaufort Sea during the Arctic voyage of the ARAON includes ice temperature/salinity and the compressive/flexural strength of sea ice. This paper analyses the gathered sea ice data in comparison with data from the first voyage of the ARAON during her Antarctic Sea ice trial.

• Journal of the Korean Society of Marine Environment & Safety
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• v.16 no.2
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• pp.153-159
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• 2010

This study looked into changes in catches of anchovy and production of sea mustard(Undaria pinnatifida) in Southern part of East Sea in Korea from 1990 to 2007 out of the fishing industry production statistics of Korea from 1969 to 2007, and then examined the relationship between the productions and the sea temperature. The production of sea mustard(Undaria pinnatifida) decreased when the sea surface temperature was high, as it adversely affected its production, while its production increased when the sea surface temperature was low, as this facilitated its growth.

• Ocean and Polar Research
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• v.21 no.2
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• pp.149-157
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• 1999

Surface sediment samples collected from the eastern half of the Yellow Sea proper in 1998 were analyzed for polycyclic aromatic hydrocarbons (PAHs), ubiquitous pollutants. Total PAHs concentrations varied from 1.0 to $320.5ng\;g^{-1}$ dw. Relatively high concentrations of PAHs were found in the muddy central part of the Yellow Sea. Sedimentary total PAHs concentrations in the Yellow Sea proper were similar to those of Californian offshores and the central Mediterranean Sea, albeit an order of magnitude lower than the Yellow Sea nearshore areas. Phenanthene/Anthracene concentration ratio of PAHs in bottom sediments suggested that pyrolytic PAHs might be dominant over petrogenic ones in the eastern Yellow Sea. Downcore depth distributions of PAHs from the relatively undisturbed core samples of the central Yellow Sea showed decreasing PAHs concentrations with core depths and suggested that the Yellow Sea has been increasingly exposed to PAH for decades. Annual total PAH flux to these sediments was estimated to be $166{\mu}gm^{-2}yr^{-1}$ in the central part of the Yellow Sea for the recent decade.

• Journal of Fisheries and Marine Sciences Education
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• v.27 no.3
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• pp.696-705
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• 2015

Approximately 4,000 vessels including sea trial ships per day are passing, entering or departing from Korea coastal waterway. Sea trial ships have erratic navigating patterns such as quick turning, crash stop and do not communicate with other vessels in appropriate time, so sea trial ships are often to expose dangerous situation such as collision in heavy traffic area. To identify the sea trial vessel's risk factors, this paper surveyed marine traffic volumes for 7 days in Korea harbour & coastal waterway, and it analyzed marine accident rate and intended to identify the risk degree of passing vessels. After that, this researched how many sea trial ship's traffic and what is the sea trial risk among sea trial items. We also conducted survey questionnaire and identified risk factors of sea trial ship. So this paper aimed to enhance the safety of korea coastal waterway to prevent sea trial ship's marine accident.

• Korean Journal of Remote Sensing
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• v.18 no.3
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• pp.127-139
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• 2002

A comparison was made between the chlorophyll $\alpha$ and suspended solid (SS) retrievals from OSMI and SeaWiFS sensor to chlorophyll $\alpha$ and SS values determined with the standard method during the NFRDI's research cruises. The percentage of organic and inorganic materials from the SS was calculated to study the contribution of turbid water in the northern part of the East China Sea. The open sea waters in the Kuroshio regions of the East China Sea showed relatively higher concentration of volatile SS. However, towards the northwestern part of the East China Sea, the situation became much more optically different with the non-volatile SS from the Yangtze river and the sea bottom sources in the sea in winter and spring seasons. Furthermore, in order to indirectly detect low salinity water with high turbidity, which related to the Yangtze river using remote sensed data from the satellites, a comparison between the results of the band ratio(nLw 490nm/nLw 555nm) of SeaWiFS(OSMI) and the distribution of low salinity around the Jeju Island was presented.

• Journal of Fisheries and Marine Sciences Education
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• v.12 no.2
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• pp.199-212
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• 2000

It is very important to investigate the hull response of a fishing vessel in the sea to ensure the safe navigation and fishing operation in rough sea by preserving excellent sea keeping qualities. For this purpose, the author measured various responses of three stem trawlers in waves using real sea experimental measuring system. The author analyzed the experimental data using the statistical and spectral analyzing method to get the characteristics of the motion responses of the vessels according to the wave height and the ship's speed. The results obtained can be summarized as follows ; (1) Rather higher response of the pitch motion due to the wave height appeared in the head sea and the bow sea than any other wave direction without relevance to ship's size. In case of the roll motion, the beam sea and the quartering sea have a high response value. The period of peak of the pitch motion and the roll motion according to the wave height in each vessel has almost same value respectively. (2) The change of response of the pitch motions deeply depend on the ship's speed in the head sea and the bow sea, but not in the other wave direction. (3) The change of response of the roll motions in the beam sea, the quartering sea and the following sea are affected by the influence of the ship's speed in 5k't to 8k't, but not related to the ship's speed in out of that range.

• Journal of Ocean Engineering and Technology
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• v.25 no.2
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• pp.55-61
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• 2011

A field trial in an ice-covered sea is one of the most important tasks in the design of icebreaking ships and offshore structures. To correctly estimate the ice load and ice resistance of a ship's hull, it is essential to understand the material properties of sea ice during ice field trials and to use the proper experimental procedure for gathering effective ice data. The first Korean-made icebreaking research vessel, "ARAON," had her second sea ice trial in the Arctic Ocean during the summer season of 2010. This paper describes the test procedures used to obtain proper sea ice data, which provides the basic information for the ship's performance in an ice-covered sea and is used to estimate the correct ice load and ice resistance of the IBRV ARAON. The data gathered from the sea ice in the Chukchi Sea and Beaufort Sea during the Arctic voyage of the ARAON includes the temperature, density, and salinity of the sea ice, which was believed to be from two-year old ice floes. This paper analyses the gathered sea ice data in comparison with data from the first voyage of the ARAON during her Antarctic Sea ice trial.

• Journal of Navigation and Port Research
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• v.32 no.5
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• pp.403-407
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• 2008

Relations between variation of SSTs(sea surface temperatures) in the South Sea of Korea and intensity of typhoons which passed through the South Sea of Korea was analyzed for 36 years from 1970 to 2005. The SSTs in the South Sea show the rising trends continuously. The mean SST of the last 10 years(1996-2005) is higher $1.03^{\circ}C$ than the mean SST during 10 years(1970-1979). The rising trends are especially strong after 1994. The intensity of typhoon can be shown by the minimum sea level pressure. The minimum sea level pressures of typhoons which passed through the South Sea show the descending trends. The mean minimum sea level pressure of the last 10 years(1996-2005) is lower 10.1hPa than that during 10 years(1970-1979). The correlation analysis shows that the rising of SSTs in the South Sea has relations with the strengthening of intensity of typhoons.